Characterization of Electrical Properties and Structural Material of LiFePO4 Cathodes Under Various Conditioning Treatments

Lithium-ion (Li-ion) batteries play a crucial role in energy storage, user safety, and device longevity in everyday applications. Among the various types, lithium iron phosphate ($\text{LiFePO}_{4}$) batteries are widely used, particularly in electric vehicles. However, like all Li-ion batteries, they eventually become waste once they reach the end of their service life. This study investigates the correlation between the electrical properties and structural characteristics of Li-ion battery cathode materials under varying load conditions. The analysis involves measuring the State of Charge (SOC) and State of Health (SOH), as well as conducting Scanning Electron Microscopy (SEM) imaging at three magnifications: $2500 \times(50 \mu ~\mathrm{m}), 5000 \times(30 \mu ~\mathrm{m})$, and $10,000 \times(10 \mu ~\mathrm{m})$ for samples A, B, C, and D. The results show a clear declining trend in SOC and SOH values with an increasing number of charge-discharge cycles. Furthermore, the findings reveal a direct correlation between the structural integrity of the $\text{LiFePO}_{4}$ cathode material and its electrical performance. Structural degradation-characterized by fragmentation and particle agglomeration - was found to contribute to reduced electrical performance, as reflected by the decreasing SOC and SOH values.